Preparation of activated carbons with high specific surface areas using lignin and crab shells, and their use in methane adsorption

Abstract

Methane gas is attracting much attention as an environmentally friendly alternative to petroleum. We have developed a high-safety and low-cost method for methane gas storage on activated carbons (ACs) prepared from biomass waste, to enable methane gas to be used effectively and safely. The ACs were prepared by the chemical activation of lignin and crab shell biomass waste with K2CO3. The optimum activated pore structure was determined using N2 adsorption isotherms, to enable the preparation of ACs with high methane adsorption capacities. The adsorption capacities of the prepared ACs and that of a commercially available active carbon were compared based on their methane adsorption isotherms at 298 K. The AC prepared from a mixture of lignin and crab shells had a maximum specific surface area of 3119 m2 g-1. The methane adsorption capacities of the ACs were particularly influenced by their micropore volumes.